Australia’s Future Energy Resources (AFER) Project: Hydrocarbon Resources Assessment, Pedirka and western Eromanga basins  


Authors / CoAuthors

Iwanec, J. | Bradshaw, B. | Ferdinando, D. | Beattie, M. | Bernecker, T. | Cebastiant, A. | Lund, D.

Abstract

<div>Understanding the hydrocarbon potential of Australia’s sedimentary basins is critical to ensuring the nation’s future energy security. The Pedirka and western Eromanga basins have proven petroleum potential with a sub-commercial oil discovery at Poolowanna 1 in the Poolowanna Trough and several wells drilled over the Colson Shelf and Madigan Trough showing evidence for residual oil zones. However, these basins remain relatively underexplored with only 42 petroleum wells drilled and relatively sparse 2D seismic data coverage. Geoscience Australia’s AFER Project has undertaken a qualitative and quantitative play-based assessment of the Pedirka and western Eromanga basins to enable a better understanding of their undiscovered hydrocarbon resources.</div><div><br></div><div>The AFER Project’s assessments are underpinned by new geological insights into the western Eromanga Basin and a supporting upscaled 3D geological model. A play-based common risk segment (CRS) mapping approach has been applied to eleven play intervals to delineate basin areas with relatively high prospectivity based on five geological risk elements: reservoir presence, reservoir effectiveness, top seal, trap presence, and hydrocarbon charge. Results from this qualitative component of the assessment indicate that the highest potential for future hydrocarbon discoveries is likely to be conventional oil resources across the Poolowanna Trough, Colson Shelf and Madigan Trough. The most prospective exploration targets are the Namur-Murta, Poolowanna and Peera Peera play intervals on a geological probability of success basis. The Peera Peera and Poolowanna play intervals have proven hydrocarbon charge from the Poolowanna 1 oil discovery but show poor reservoir quality (porosity <10%) in wells drilled across the Poolowanna Trough. These play intervals likely represent tight conventional oil exploration targets across their main play fairways in the Poolowanna Trough. The Namur-Murta interval has high reservoir qualities across all potentially prospective areas but has lower certainty regarding hydrocarbon charge with the most significant exploration result to date being a residual oil zone in the Madigan Trough. Moderate to high prospectivity for conventional oil is interpreted to occur in the Adori-Westbourne, Birkhead and Hutton play intervals over the eastern flanks of the Poolowanna Trough and western flanks of the Birdsville Track Ridge. The Walkandi, Upper Purni, Lower Purni and Crown Point play intervals are assessed as having moderate prospectivity for conventional oil over the Eringa Trough, Madigan Trough and Colson Shelf. </div><div><br></div><div>A quantitative assessment of the ‘Yet to Find’ hydrocarbon volumes has been undertaken to provide a play-level indication of the possible undiscovered conventional oil volumes. The risked volumes include a ‘Base Case’ that reflects the current exploration understanding of the basins, and a ‘High Case’ that reflects the potential impact of a new working petroleum system being discovered in the basins. The mean risked recoverable oil volume for the Base Case scenario total 22.2 MMbbl for the four plays evaluated (Namur-Murta, Poolowanna, Peera Peera and Lower Purni). About 70% of the risked mean volumes occur in the Poolowanna and Namur-Murta play intervals. Results from the High Case model highlight the significantly greater YTF potential across the basins if the geological requirement for a new working petroleum system eventuates from further exploration, with a total mean risked volume of 234.8 MMbbl for the three play intervals evaluated (Namur-Murta, Poolowanna and Lower Purni). Risked volumes are relatively evenly distributed across the three play intervals. &nbsp;&nbsp;</div><div><br></div><div>Unconventional hydrocarbons are evaluated as being less prospective than conventional hydrocarbons in the western Eromanga basin. Shale oil plays have not previously been explored but may be present within organic-rich shales from the Poolowanna and Peera Peera play intervals. These shale oil plays are evaluated as being moderately prospectivity due to their thin and heterogeneous character. Coal seam gas (CSG) wells drilled into the Upper Purni and Lower Purni play intervals have to date only demonstrated the presence of gas-undersaturated coal seams over the Andado Shelf. However, CSG is the most likely hydrocarbon resource type to produce hydrocarbons from the Pedirka Basin if future exploration can identify sweet spots where different geological conditions occur that are conducive to preserving high gas saturations.&nbsp;</div><div><br></div>

Product Type

document

eCat Id

149673

Contact for the resource

  Resource provider

 

  Point of contact

Commonwealth of Australia (Geoscience Australia)  
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

  Point of contact

 

Digital Object Identifier

https://dx.doi.org/10.26186/149673

Keywords

( Project )
  • EFTF – Exploring for the Future
( Project )
  • Australia’s Future Energy Resources
( Project )
  • Energy Resource Assessment Module
  • hydrocarbon prospectivity
  • Conventional Hydrocarbons
  • Unconventional Hydrocarbons
  • Pedirka Basin
  • western Eromanga Basin
theme.ANZRC Fields of Research.rdf
  • Resource geoscience
  • Published_External

Publication Date

2024-08-15T01:27:56

Creation Date

2024-06-19T00:00:00

Security Constraints

Australian Government Security Classification System    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Use - license otherRestrictions

Status

Purpose

The product provides a high-level overview of the AFER Project's play-based assessment of hydrocarbon resources in the Pedirka and western Eromanga Basin to inform regulators and policy makers at State/Territory and Federal government levels, as well as energy industry stakeholders.

Maintenance Information

notPlanned

Topic Category

geoscientificInformation

Series Information

GA Record 2024/39

Lineage

<div>The report summarises the workflows and results from the qualitative and quantitative analysis for Hydrocarbon Resources in the Pedirka and western Eromanga basins, which are also available in a related digital data package (ECAT 149501).</div>

Parent Information

Extents

[-44, -9, 112, 154]

Reference System

Spatial Resolution

Service Information

Associations

Association Type - wasInformedBy

Australia's Future Energy Resources (AFER) Project: Assessment of the geological storage potential for carbon dioxide, Pedirka and western Eromanga basins    

eCat Identifier - 149622,

UUID - 1128ba1e-678a-4280-b028-0ec759bcc7c3

Association Type - wasInformedBy

Pedirka and Western Eromanga seismic interpretations Data package and explanatory notes    

eCat Identifier - 149068,

UUID - 38582f5f-022d-4346-bd86-333e67315afb

Association Type - wasDerivedFrom

Pedirka and western Eromanga basins energy resource assessments Data package and metadata    

eCat Identifier - 149501,

UUID - 7e1d7cd0-3915-4a28-a0a2-b110dcd644b7

Association Type - wasInformedBy

Pedirka and Western Eromanga basins gross depositional environment interpretations    

eCat Identifier - 148900,

UUID - b8c94cbe-76f0-45d7-b816-f6027dd600f5

Association Type - wasInformedBy

Pedirka and western Eromanga basins depth and isochore maps - Data package and explanatory notes    

eCat Identifier - 149124,

UUID - 089ef6a8-ab28-4595-ab41-c06b1a8e3828

Association Type - wasInformedBy

The Pedirka and western Eromanga basins well log petrophysics data package    

eCat Identifier - 149208,

UUID - 8950e58a-d553-476c-b8d0-e70bbd202ae0

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Download the Record (pdf) [6.4 MB]  

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